Concerning IP

My computer is still acting up. I can't access the internet or anything. But I think I know why...
One of my mother's co-workers suggested that I tried to 'Repair' my net card. "Smashing," I thought and tried it. After a couple of minutes the screen spits something at me: "Repair failed while renewing IP-adress" (Mind you, this is a translation of the Danish angry looking sign, so it might not be 100% accurate)
My question is: Can I force a new (or force a renewing) IP-adress on my net card? Based on the angy sign, I think that it has a wrong IP-adress, and that's causing me to be completely without internet.
I know there's some prompts or whatever they are called (You know, press Star, pick Run and then input something like configip) but I can't remember any of them, and don't know if any of them actually can help.

(And deleting the card and installing it again didn't help anything, sadly )

Jam it back in, in the dark.